The invention relates to a method to pattern and etch submicron pillars using photolithography and etch techniques.
In semiconductor devices it may be necessary to pattern and etch submicron pillars. An example is found in Herner et al., U.S. patent application Ser. No. 10/326,470, hereinafter the '470 application (since abandoned), herein incorporated by reference, which requires an array of pillars having submicron dimensions to be formed using conventional photolithography and etch processes. Photoresist is patterned and developed into photoresist features, which are then etched into an underlying material. Even at very small critical dimensions (CDs), photoresist lines are mechanically strong enough to survive the exposure, development, and the cleaning and drying process that follows before the etch is performed. At the same CDs, however, photoresist pillars have less mechanical strength and may topple before the etch can be performed.
There is a need, therefore, for a method to pattern and etch very small pillars using standard photolithography and etch methods.